1. Department of Engineering Mechanics, Royal Institute of Technology, 100 44 Stockholm, Sweden
2. FLOW, Royal Institute of Technology, 100 44 Stockholm, Sweden
3. Treesearch, Royal Institute of Technology, 100 44 Stockholm, Sweden
4. Wallenberg Wood Science Center, Royal Institute of Technology, 100 44 Stockholm, Sweden
5. Department of Fibre and Polymer Technology, Royal Institute of Technology, 100 44 Stockholm, Sweden
6. Deutches Elektronen-Synchrotron DESY, 22607 Hamburg, Germany